Neutron Star Merger Dynamics www.computational-relativity.org - PowerPoint PPT Presentation

Neutron Star Merger Dynamics www.computational-relativity.org arXiv:2002.03863 David Radice — October 27, 2020

GW170817 From LIGO Scientific Collaboration and Virgo Collaboration, Fermi GBM, INTEGRAL, IceCube Collaboration, AstroSat Cadmium Zinc Telluride Imager Team, IPN Collaboration, The Insight-Hxmt Collaboration, ANTARES Collaboration, The Swift Collaboration, AGILE Team, The 1M2H Team, The Dark Energy Camera GW-EM Collaboration and the DES Collaboration, The DLT40 Collaboration, GRAWITA: GRAvitational Wave Inaf TeAm, The Fermi Large Area Telescope Collaboration, ATCA: Australia Telescope Compact Array, ASKAP: Australian SKA Pathfinder, Las Cumbres Observatory Group, OzGrav, DWF (Deeper, Wider, Faster Program), AST3, and CAASTRO Collaborations, The VINROUGE Collaboration, MASTER Collaboration, J-GEM, GROWTH, JAGWAR, Caltech- NRAO, TTU-NRAO, and NuSTAR Collaborations, Pan-STARRS, The MAXI Team, TZAC Consortium, KU Collaboration, Nordic Optical Telescope, ePESSTO, GROND, Texas Tech University, SALT Group, TOROS: Transient Robotic Observatory of the South Collaboration, The BOOTES Collaboration, MWA: Murchison Widefield Array, The CALET Collaboration, IKI-GW Follow-up Collaboration, H.E.S.S. Collaboration, LOFAR Collaboration, LWA: Long Wavelength Array, HAWC Collaboration, The Pierre Auger Collaboration, ALMA Collaboration, Euro VLBI Team, Pi of the Sky Collaboration, The Chandra Team at McGill University, DFN: Desert Fireball Network, ATLAS, High Time Resolution Universe Survey, RIMAS and RATIR, and SKA South Africa/MeerKAT ApJL 848:L12 (2017)

Open questions • How did these binaries form? • How do neutron star mergers power gamma-ray bursts? From LIGO Scientific Collaboration and Virgo Collaboration, Fermi GBM, INTEGRAL, IceCube Collaboration, AstroSat Cadmium Zinc • What are neutron stars made of? Nucleons, hyperons, Telluride Imager Team, IPN Collaboration, The Insight-Hxmt Collaboration, ANTARES Collaboration, The Swift Collaboration, deconfined quarks? AGILE Team, The 1M2H Team, The Dark Energy Camera GW-EM Collaboration and the DES Collaboration, The DLT40 Collaboration, GRAWITA: GRAvitational Wave Inaf TeAm, The • Was the gold in my wedding ring formed in a neutron star Fermi Large Area Telescope Collaboration, ATCA: Australia Telescope Compact Array, ASKAP: Australian SKA Pathfinder, Las Cumbres Observatory Group, OzGrav, DWF (Deeper, Wider, merger? Was it swirling around in an accretion disk? Or was it Faster Program), AST3, and CAASTRO Collaborations, The VINROUGE Collaboration, MASTER Collaboration, J-GEM, tidally ejected prior to the cataclysmic collision? GROWTH, JAGWAR, Caltech- NRAO, TTU-NRAO, and NuSTAR Collaborations, Pan-STARRS, The MAXI Team, TZAC Consortium, KU Collaboration, Nordic Optical Telescope, ePESSTO, GROND, Texas Tech University, SALT Group, TOROS: Transient Robotic Observatory of the South Collaboration, The BOOTES Collaboration, MWA: Murchison Widefield Array, The CALET Collaboration, IKI-GW Follow-up Collaboration, H.E.S.S. Collaboration, LOFAR Collaboration, LWA: Long Wavelength Array, HAWC Collaboration, The Pierre Auger Collaboration, ALMA Collaboration, Euro VLBI Team, Pi of the Sky Collaboration, The Chandra Team at McGill University, DFN: Desert Fireball Network, ATLAS, High Time Resolution Universe Survey, RIMAS and RATIR, and SKA South Africa/MeerKAT ApJL 848:L12 (2017)

WhiskyTHC http://personal.psu.edu/~dur566/whiskythc.html ● Full-GR, dynamical spacetime* ● Nuclear EOS ● Effective neutrino treatment ● High-order hydrodynamics ● Open source! * using the Einstein Toolkit metric solvers THC: Templated Hydrodynamics Code

Neutron rich outflows

Compact object + disk

Neutron star merger evolution GWs Viscosity Neutrinos

The inspiral phase

Gravitational waves GW170817 — In the frequency domain vs theory prediction https://teobresums.github.io/gwevents/

Gravitational waves GW170817 — In the frequency domain vs theory prediction https://teobresums.github.io/gwevents/

The CoRe database www.computational-relativity.org Dietrich, DR , Bernuzzi+ CQG 35:LT01 (2018)

The CoRe database Open Science • Outflow composition, mass, velocity • r-process nucleosynthesis results • Simulation code, postprocessing routines • Initial data and input files • Other data available on request www.computational-relativity.org Dietrich, DR , Bernuzzi+ CQG 35:LT01 (2018)

Early postmerger evolution z

Dynamical mass ejection See also Bausswein+ 2013, Hotokezaka+ 2013, Wanajo+ 2014, Sekiguchi+ 2015, 2016, Foucart+ 2016, Lehner+ 2016, Dietrich+ 2016, DR + 2018, … DR , Galeazzi+ MRAS 460:3255 (2016)

The kilonova in GW170817 M blue ' 0 . 02 M � , v blue ' 0 . 25 c. ej ej M red ' 0 . 05 M � , v red ' 0 . 15 c. ej ej From Villar et al. ApJL 851:L21 (2017)

Theory vs observations s [ k b /baryon] BLh q=1.00 (SR), t − t merg = 88 ms Y e Tot.Ej. Red kN [S] SLy4 50 0.45 Sec.Ej LS220 SFHo 10 ° 1 100 Blue kN [S] DD2 BLh 0.40 40 Viscous wind? 0.35 50 0.30 30 Z [km] M ej [ M Ø ] 0 0.25 10 ° 2 20 0.20 − 50 0.15 10 0.10 Spiral-wave wind? − 100 0 0.05 10 ° 3 − 100 − 50 0 50 100 X [km] Dynamical ejecta 0.05 0.10 0.15 0.20 0.25 0.30 0.35 h Y e ; ej i From Nedora, Bernuzzi, DR +, 2008.04333

Disk formation I M chirp = 1 . 188 M � Bernuzzi, …, DR +, arXiv:2003.06015

Disk formation II Prompt-BH with large disk! Bernuzzi, …, DR +, arXiv:2003.06015

Disk masses 0 Fit Fit − 1 log( M disk /M Ø ) − 2 BHB Λ φ LS220 − 3 DD2 SFHo 1 ∆ log( M disk /M Ø ) 0 − 1 0 250 500 750 1000 1250 1500 ˜ Λ DR , Perego+ ApJL 852:L29 (2018); See also Krüger+ 2020; Salafia+ 2020; … DR & Dai, Eur. Phys. J. A 55: 50 (2019)

Equation of state constraints GW Only GW + EM Prior PDF 0 200 400 600 800 1000 ˜ Λ DR , Perego+ ApJL 852:L29 (2018); See also Gamba+ 2020 DR & Dai, Eur. Phys. J. A 55: 50 (2019)

Equation of state constraints GW Only GW + EM Prior NICER PDF 6 8 10 12 14 16 R 1 . 4 [km] DR , Perego+ ApJL 852:L29 (2018); See also Gamba+ 2020 DR & Dai, Eur. Phys. J. A 55: 50 (2019)

Equation of state constraints GW Only GW Only GW + EM GW + EM Prior Prior • Potential to constrain the EOS and/or q: the basic NICER NICER physics is understood and included in the simulations PDF PDF • Modeling uncertainties appear to be under control • Need to explore the parameter space: EOS, mass ratios, etc. 6 6 8 8 10 10 12 12 14 14 16 16 R 1 . 4 [km] R 1 . 4 [km] DR , Perego+ ApJL 852:L29 (2018); DR & Dai, Eur. Phys. J. A 55: 50 (2019)

Long-term evolution

End of the GW-driven phase 10 3 DD2 – (1 . 35 + 1 . 35) M Ø – M0 DD2 – (1 . 35 + 1 . 35) M Ø – M0 10 2 J GW [s] 10 1 J/ ˙ 10 0 10 ° 1 BHB Λ φ LS220 DD2 SFHo 10 ° 2 4 . 0 4 . 5 5 . 0 5 . 5 6 . 0 6 . 5 J [ G c ° 1 M 2 Ø ] DR , Perego, Bernuzzi, Zhang, MNRAS 481:3670 (2018)

Secular evolution: NS remnants 4 . 00 3.55 BHB Λ φ BH HMNS 3 . 75 3.36 SMNS MNS 3 . 50 3.16 M b [ M Ø ] M [ M Ø ] 3 . 25 2.95 3 . 00 2.75 2 . 75 2.54 RNS RNS 2 . 50 2.32 3 4 5 6 7 8 9 J [ G c ° 1 M 2 Ø ] DR , Perego, Bernuzzi, Zhang, MNRAS 481:3670 (2018)

Spiral-wave wind (I) DD2 Dyn. LS220 Dyn. DD2 Dyn.+Wind LS220 Dyn.+Wind 10 − 1 Relative final abundances 10 − 2 10 − 3 10 − 4 50 100 150 Mass number, A M ej [10 � 2 M � ] 1 . 0 DD2 Dyn. LS220 Dyn. 0 . 5 DD2 Wind LS220 Wind 0 . 0 0 20 40 60 80 100 t � t merg [ms] From Nedora, Bernuzzi, DR +, ApJL 886:L30 (2019)

Spiral-wave wind (II) M ej [10 � 2 M � ] g band z band Ks band 16 3.0 AB magnitude at 40 Mpc 2.5 18 2.0 20 1.5 22 1.0 LS220 Viscous wind? DD2 0.5 24 AT2017gfo 10 0 10 1 10 0 10 1 10 0 10 1 time [days] time [days] time [days] Promising, but incomplete, and not the only possible explanation From Nedora, Bernuzzi, DR +, ApJL 886:L30 (2019)

Future Challenges

Neutrino physics From Sekiguchi+ 2011 See also: Dessart+ 2008, Perego+ 2014, Just+ 2015, Metzger+ 2014, Foucart+ 2016, Siegel & Metzger 2018, Fujibayashi+ 2017, 2020 … From Miller+ 2019

MHD turbulence Siegel & Metzger 2018 Kiuchi+ 2014 See also Price & Rosswog 2006; Andreson+ 2008; Etienne+ 2011; Endrizzi+ 2014; Giacomazzo+ 2015; Ruiz+ 2016; Palenzuela+ 2016; Fernandez+ 2018; Mösta, DR +, ApJL 2020 Ciolfi+ 2019; …

Merger outcome BLh* q=1.00 (SR) 3.000 2.72 2.975 2.69 2.950 2.67 M b [ M � ] M [ M � ] 2.925 2.64 J ADM � J GW 2.900 Expected Evolution M b , J evolution (3D data) 2.62 2.875 extrapolation (every 50 ms) RNS 2.850 2.59 4 5 6 J [ G c � 1 M 2 � ] From Nedora, Bernuzzi, DR +, 2008.04333

Conclusions • Inspiral and early postmerger are better understood, but there is still a vast parameter space volume to explore. • We can already do multimessenger astrophysics! • The physics becomes increasingly complex on longer timescales in the postmerger. Higher resolution, longer, and more sophisticated simulations are needed.